BACKGROUND: The optimal timing to start androgen deprivation therapy (ADT) in prostate cancer patients with rising prostate-specific antigen (PSA) as the only sign of relapse is unknown.
METHODS: We identified men with prostate cancer in the Cancer of the Prostate Strategic Urologic Research Endeavour (CaPSURE) study who would have been eligible (⩽ cT3aN0M0, primary radical prostatectomy or radiotherapy, PSA relapse as the only evidence of recurrence) for a randomised trial comparing 'immediate' versus 'deferred' ADT initiation. We emulated such trial by assigning patients to the 'immediate' strategy if they initiated ADT within 3months of PSA relapse and to the 'deferred' strategy if they initiated ADT when they presented with metastasis, symptoms or a short PSA doubling time. We censored patients when they deviated from the assigned strategy and adjusted for this censoring via inverse probability weighting.
RESULTS: Of 2096 eligible patients (median age 69, interquartile range 63-75years), 88% were white, 35% had a Gleason score ⩾7, 69% were treated with radical prostatectomy and 31% received radiotherapy only as primary treatment. The mean time from primary treatment to PSA relapse was 37.4 (standard deviation [SD] 34.2) months. Mean follow-up from primary treatment was 91.4 (SD 48.4) months. The adjusted mortality hazard ratio for immediate versus deferred ADT was 0.91 (95% confidence interval (CI), 0.52-1.60), which would be translated into a similar 5-year survival (difference between groups: -2.0% (95% CI: -10.0 to 5.9%).
CONCLUSION: Our analysis suggests that prostate cancer patients undergoing immediate ADT initiation within three months after PSA-only relapse had similar survival to those who deferred ADT initiation within 3months after clinical progression.
Garcia-Albeniz X, Chan JM, Paciorek A, Logan RW, Kenfield SA, Cooperberg MR, Carroll PR, Hernán MA. Are you the author?
Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, United States; Departments of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, United States; Department of Urology, University of California, San Francisco, San Francisco, CA, United States; Harvard-MIT Division of Health Sciences and Technology, Boston, MA, United States.
Reference: Eur J Cancer. 2015 May;51(7):817-24.